The present invention relates generally to cross-linked polymeric compositions and to a method of application of such compositions.
U.S. Pat. No. 6,063,061, owned by eventual the assignee of the present invention, the entire contents of which are incorporated herein expressly by reference, describes biocompatible polymeric compositions for application at target sites in a patient's body. The reference describes that one particular use of the compositions is for preventing or inhibiting the formation of tissue adhesions, such as spinal tissue adhesions, following surgery and traumatic injury.
The compositions include a molecular, cross-linked hydrogel, which is configured to enhance its flowability (e.g. the ability to be extruded through a syringe) and its ability to flow onto and conform to sites on or in tissue, including tissue surfaces and defined cavities, e.g. intravertebral spaces, tissue divots, holes, pockets, and the like.
In particular, the gel is taught to flow when the compositions are subjected to stresses above a threshold level, for example when extruded through an orifice or cannula or when packed into a delivery site using a spatula, or the like. The threshold stresses are specified to be in a range from 3×104 Pa to 5×105 Pa. The compositions, however, remain generally immobile when subjected to stresses below the specified levels.
The gels are taught to be packed in a syringe, for example, prior to mechanical disruption. The materials are mechanically disrupted as they are applied through the syringe to the tissue target site. Alternatively, the material is taught to be a cross-linked polymeric material that is stored in a dry form prior to use. The dry material is then loaded into a syringe, for example, hydrated within the syringe, and mechanically disrupted as the material is delivered to the target site.
While the above-described composition has been used effectively in applications that may be reached via a syringe or spatula, e.g., inhibiting tissue adhesions at the spine, the composition is too viscous to be delivered through a long, narrow catheter. Accordingly, the composition has not been used in a typical way for applications requiring such long, narrow catheters, such as wounds, abrasions, cuts or lesions located inside a person's gastrointestinal track.
It is therefore desirable to provide an apparatus and method for supplying the above-described composition, and other target site compositions of similar viscosity, to locations and applications in a mammalian body that require a relatively long and narrow catheter or other passageway for access.